The small particle size of biological agents requires a complex identification process and detectors. At the same time ultrafine particles remain a powerful concept in the toxicology. For example, polycyclic aromatic hydrocarbons (PAHs) adsorbed on atmospheric particles are of concern because PAHs are known to be mutagenic. Besides toxic effects ultrafine particles can cause coronary and ischemic heart diseases, asthma, and other lung and respiratory diseases. Current biological agent detection systems are large, complex, expensive, and subject to false alarms. They can detect only a limited number of biological agents and only after exposure. Sensitivity, selectivity, and durability of these detection technologies are not proven. The technology proposed in this project can significantly reduce the current drawbacks of the existing aerosol characterization techniques by implementing a combination of several unique and powerful techniques in a single compact multifunctional device. The objective of this project is to develop optoelectronic modules, capable of fluorescence, absorption, and scattering measurements, integrated with a Time-of-Flight (TOF) mass spectrometer for advanced analysis of ultrafine aerosol particles and MALDI experiments. The specific Phase I aims are: 1. Fabrication and characterization of an ultrafine particle detector prototype based on scattering for determination of TOF starting point for individual particles and size identification; 2. Fabrication and characterization of a fluorescence module prototype for analyte characterization prior to mass spectrometry; 3. Integration of the prototypes within an ORTOF mass spectrometer; 4. Testing of the integrated setup and evaluation of its characteristics. The Phase II will focus on: 1. Miniaturization of the optoelectronic modules through components integration on a single substrate; 2. Development of UV components (LED and lasers) integrated into a particulate detection module for sizes less than 100 nm; 3. Integration of the micro-fabricated optoelectronic modules into the unconventional ORTOF mass spectrometer. [unreadable] [unreadable]